Hello all,
Non-engineer here (Fish Biologist), so go easy on me. I'll *try* to keep this brief. I've been running a fish tracking project for several years in a unique river system. This design is for deploying submersed receiver devices in areas where only a permanent natural structure is available (bedrock bank line, large boulders, etc.). We try to place everything on the downstream side for protection from high current and floating debris. My current issue is our equipment being buried in feet of sand. We did try just having a U-shaped bar on top of the anchor for the cable, but that didn't help.
Would appreciate any suggestions on how we can make this design better.
I won't hold anyone liable, I promise!
Equipment & research considerations:
- Receiver devices deployed at strategic locations along several hundred river miles
- Receivers must be accessible monthly & re-deployable without divers
- Receiver must have the clearest view possible of river channel. Antenna is omnidirectional but acoustic signal can be impeded by rock, sand humps, etc.
- Budget is tight, acoustic release not an option. Water isn't clear enough for ROV use
- Deployment and recoveries must not require more than 3 people
Environmental factors:
- Extreme hydrological fluctuations. Average depth of 6 inches to 3' can reach 10-25 ft during dam releases or floods (this is often weekly)
- Sediment transport is insane. There are very few areas of rock bottoms, and those will also cover with sand for some extent of time
- Very large trees, float downstream and will catch anything in their path (surface buoys & exposed cable didn't go well)
- The water has high salinity (almost brackish), so it's very corrosive
- Boat traffic is almost nonexistent. The river is very remote